Germany's conservative leader Friedrich Merz will face a second vote in parliament on Tuesday in his bid to become chancellor after he lost the first round in a stunning early setback.

Even if he succeeds in becoming post-war Germany's 10th chancellor, the initial shock defeat dealt a heavy blow to Merz, who has vowed to restore stability in Berlin after half a year of political turmoil.

Merz, 69, whose CDU/CSU alliance won elections in February, has agreed on a coalition government with the center-left Social Democrats (SPD) of outgoing Chancellor Olaf Scholz.